The present invention relates to a surgical instrument and more particularly to an improved surgical wire driving assembly, in which a wire member may be positively driven, fed out of the assembly in variable controlled lengths, and manually released or engaged in a simple, reliable and efficient manner without the need for extra tools such as keys and the like.
It has been known in the prior art to use a collet-type device which is tightened around a wire-type member to drive the member in a rotary manner. In order to feed the wire member with such device, it is necessary to loosen the collet, feed the wire and re-tighten the collet to establish a driving relation between the collet assembly and the wire member.
In surgical procedures in which osteologist is repairing fractured or broken bones, it is now a common procedure to secure the fractured or broken bones by what is known as a "pin". In reality, the pin is a relatively stiff wire usually of stainless steel.
As will be apparent, it is necessary in such a procedure that the surgeon have positive control of the wire such that it can be driven with precision and accurate control into a desired point in the bone structure. For example, the length of wire between the bone and the face of the driving tool is normally controlled such that it does not become too long since that tends to cause the wire to wobble. The principal force for causing the wire to enter the bone is the pressure applied by the surgeon during the driving operation. Thus, in a typical procedure, the surgeon advances the wire to a certain depth into the bone, retracts the driving tool to provide an additional controlled length of wire, then continues the procedure, severing the wire after an appropriate length of wire has been inserted into the bone.
In some instances, it is necessary for the surgeon to work in areas which are not readily accessible, such as the space between the fingers of an infant. In such an instance, cumbersome and bulky surgical instruments or extra devices needed to release the driver only tend to complicate what might already be a complicated surgical procedure. Moreover, the patient is usually under anesthesia during the procedure and thus any manipulations of a relatively complex nature related to adjustment or operation of the surgical instrument only increases the time for the procedure. This is generally objectionable. For example, if time is taken from the actual procedure to adjust or re-adjust the instrument, there is objection. The operation of the instrument must be efficient, reliable and uncomplicated simply to reduce the total time of the procedure. Thus, there is objection to the use of keys or any other separate free element for tightening or releasing a collet due to the manipulative steps involved.
Release of the wire must be accomplished effectively without forward movement of the front end of the instrument. Usually, the wire extends beyond the front end of the driver assembly and sometimes it is necessary for the surgeon to position the front of the driver against the patient's skin or bone. Release of the wire must be accomplished effectively without the need to use separate unlocking devices such as keys and without moving the front of the driver forward since, in such a case, there is little if any space between the front of the driver and the patient's skin or bone.